Semiconductor lasers may be used in the fields of optical communication, laser printers, optical pickups for information recording disks, and the like. A semiconductor laser has a layered structure including an active layer having a predetermined bandgap. A laser beam is oscillated by utilizing recombination light emission of carriers injected into the active layer and optical resonance using cleaved end faces, a diffraction grating, or the like.
Related art is disclosed, for example, in Japanese Laid-open Patent Publication No. 2008-028374.